Presently, diesel engines include a piston and cylinder arrangement in which the piston rod is connected to a crankshaft and supports the piston within a cylinder. The rotation of the crankshaft causes the piston rod to move upwardly and downwardly and, as a result, causes the piston to move upwardly and downwardly within the cylinder. Presently, the beginning torque of the crank is zero ft./lbs. at the top dead center to about 10.degree. past this point. The knocking noise of an idling diesel engine is due to the beginning explosive force that continues to about 30.degree. or more, past the top dead center torque. As a result, the early torque generated by the diesel engine is less than optimal. Because of the faulty early torque of such a diesel engine is the inadequate geometrical relationship between the piston rod and the crankshaft.
U.S. Pat. No. 5,555,777, which issued to the present inventor on a related apparatus, describes a crank apparatus for the crankshaft of a diesel engine. In this crank apparatus, the device included a crank pin having a first tab extending outwardly from one side of the crank pin and a second tab extending outwardly from an opposite side of the crank pin. A split sleeve was provided that had an elongated slot therein. The slot receives the crank pin therein such that one of the tabs extended through an opening from the slot of the split sleeve. The piston rod was bearingly interconnected to the split sleeve. The bearing connection has an insert key connected thereto and residing within the split sleeve in a position so as to contact the crank pin upon a rotation of the crankshaft. The insert key was positioned so as to have a portion residing within the interior area between the first and second portions of the split sleeve. As such, during a rotation of the crankshaft, the tabs of the split sleeve would contact the insert key so as to cause the crank pin to slide back and forth within the elongated slot. After experimentation, it was found that this configuration did not provide enough surface contact area between the insert key and the tabs. As such, there was some "slapping" contact between the crank pin and the bearing surface during the rotation of the crankshaft. The present invention is an improvement on the teachings of the present inventor's U.S. Pat. No. 5,555,777.
U.S. application Ser. No. 08/834,132, filed on Apr. 14, 1997, by the present inventor also describes an improved crank apparatus for a diesel engine. This crank apparatus includes a crankshaft, an arm extending outwardly of the crankshaft, a crank pin affixed to the arm and having a generally rectangular configuration, a sleeve member having an elongated rectangular slot formed therein, and a piston rod having a circular bearing area receiving the sleeve member therein. The crank pin is slidable in the rectangular slot relative to a rotation of the crankshaft. The sleeve member has a smaller diameter than the circular bearing area. The circular bearing area has an insert key positioned therein. This insert key bears on a surface of the sleeve member during the rotation of the crankshaft. The sleeve member is a split sleeve having a first portion and a second portion affixed together around the crank pin. The sleeve member is split diagonally thereacross. The tapered sides of these sleeve members are affixed together in surface-to-surface contact through the use of doweled members. The piston rod has split caps extending around the sleeve member. The split caps define the circular bearing area. The insert key is affixed in one of the split caps. Specifically, the insert key is inserted within an interior cavity of one of the split caps. The insert key is positioned so as to have an edge extending into the circular bearing area. The sleeve member contacts the insert key at a point offset by approximately 70.degree. from a centerline of the piston rod when the piston is in its furthest point from the crankshaft. In particular, the sleeve member will bear on a surface of the circular bearing area during the rotation of the crankshaft. During the rotation of the crank, the sleeve member will shift over the crank pin. On the "downstroke", it will shift to one side. On the "upstroke", the sleeve will shift to the opposite side. In this turning process, the round outer diameter of the sleeve actually rolls and slides in constant contact with the rod's bearing surface without any slapping during the crank pin and rod angle shifting in one revolution. The particular arrangement of the present invention provides a "top dead off center" at about a seven degree offset position advance at the high position of the piston so as to eliminate most of the beginning stress in such internal combustion engine.
It is an object of the present invention to provide an improved crank apparatus to improve the efficiency of the crank mechanism of an internal combustion engine.
It is another object of the present invention to provide a crank apparatus for an engine that enhances the torque at the top dead center of the crank.
It is a further object of the present invention to provide an improved crank apparatus that improves fuel economy, increases power, and eliminates the knocking noise of the diesel engine.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.